The repeat atoms can be whatever metal I want, so I went with ones that helped compensate for the lack or excess of quicksilver.

35a would require a fixed piston and a geometry such that the two hexes of the bonder are unusable for shuffling, just bonding. This is already tight even with track translation and three extra hexes (bonder and track) to play with, so I bet one HubrisCoin on "35a is not happening".